Abstract: Bimodal resin products are produced in a single reactor by using two bicomponent catalyst compositions, each having a high molecular weight and a low molecular weight component, in different ratios. The HMW/LMW split of the final resin product is controlled accurately by controlling the ratio of the feed of the two bicomponent catalyst compositions. Bimodal or polymodal effects are also achieved for properties or characteristics other than molecular weight. More complex results can be achieved with more than two components. The invention is applicable to a wide variety of polymer products, particularly polyolefins and polyethylene.

Abstract: A process for production of a polyethylene blend in situ comprising contacting ethylene and at least one alpha-olefin with a magnesium/titanium based catalyst system including a partially activated precursor and a cocatalyst in each of two fluidized bed reactors connected in series, one of the provisos being that the precursor is formed by contacting an alkylaluminum halide with a solid reaction product prepared from a magnesium alkoxide, a titanium tetraalkoxide, and a solubility enhancing agent.